Block #2,818,066

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 8/31/2018, 7:03:57 AM · Difficulty 11.6969 · 4,022,168 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
152d553e165e03f3b28abe1b45033b5ebbba6f1c3c5afc0cf3c3099e548759eb

Height

#2,818,066

Difficulty

11.696933

Transactions

2

Size

571 B

Version

2

Bits

0bb26a2f

Nonce

1,570,407,084

Timestamp

8/31/2018, 7:03:57 AM

Confirmations

4,022,168

Merkle Root

52da7fb64b412402c9e96512ce2f048d455f2e3ffcf43d5436b3436156f3ccc0
Transactions (2)
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

4.306 × 10⁹¹(92-digit number)
43061603937741039729…87698162616043515169
Discovered Prime Numbers
p_k = 2^k × origin − 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin − 1
4.306 × 10⁹¹(92-digit number)
43061603937741039729…87698162616043515169
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.612 × 10⁹¹(92-digit number)
86123207875482079459…75396325232087030339
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.722 × 10⁹²(93-digit number)
17224641575096415891…50792650464174060679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.444 × 10⁹²(93-digit number)
34449283150192831783…01585300928348121359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.889 × 10⁹²(93-digit number)
68898566300385663567…03170601856696242719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.377 × 10⁹³(94-digit number)
13779713260077132713…06341203713392485439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.755 × 10⁹³(94-digit number)
27559426520154265427…12682407426784970879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.511 × 10⁹³(94-digit number)
55118853040308530854…25364814853569941759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.102 × 10⁹⁴(95-digit number)
11023770608061706170…50729629707139883519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.204 × 10⁹⁴(95-digit number)
22047541216123412341…01459259414279767039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
4.409 × 10⁹⁴(95-digit number)
44095082432246824683…02918518828559534079
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

★★★☆☆
Rarity
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,966,183 XPM·at block #6,840,233 · updates every 60s
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